Refrigerator using non-azeotropic refrigerant mixture and control method thereof

Abstract

A refrigerator using a non-azeotropic refrigerant mixture (NARM) and a control method thereof. The refrigerator reduces the rotational speed of a freezing chamber fan or stopping the freezing chamber fan for a designated time, and/or increasing the rotational speed of a compressor in a simultaneous freezing/refrigerating operation mode of an NARM cycle as compared to a freezing operation mode, and may thus decrease evaporation latent heat of a refrigerant consumed by a freezing chamber evaporator and relatively increase evaporation latent heat of the refrigerant usable in a refrigerating chamber evaporator without increase in a charging amount of the refrigerant, thereby preventing over-charging due to increase in the charging amount of the refrigerant and reducing cycling loss.

What is claimed is: 
     
         1 . A refrigerator comprising:
 a freezing chamber and a refrigerating chamber;   a compressor to compress a refrigerant;   a refrigerating chamber evaporator to cool the refrigerating chamber;   a freezing chamber evaporator provided at an upstream position as compared to a position of the refrigerating chamber evaporator, and to cool the freezing chamber;   a freezing chamber fan to blow cool air having undergone heat exchange in the freezing chamber evaporator; and   a controller to control operations of the compressor and the freezing chamber fan,   wherein the refrigerator has a freezing operation mode and a simultaneous freezing/refrigerating operation mode, and   wherein the controller changes a rotational speed of at least one of the freezing chamber fan and the compressor so as to increase evaporation latent heat of the refrigerant introduced into the refrigerating chamber evaporator in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode.   
     
     
         2 . The refrigerator according to  claim 1 , wherein the controller lowers the rotational speed of the freezing chamber fan in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         3 . The refrigerator according to  claim 1 , wherein the controller temporarily stops the rotational speed of the freezing chamber fan in the simultaneous freezing/refrigerating operation mode. 
     
     
         4 . The refrigerator according to  claim 1 , wherein the controller increases the rotational speed of the compressor in the simultaneous freezing/refrigerating operation mode as compared to a freezing operation mode. 
     
     
         5 . The refrigerator according to  claim 1 , wherein the controller lowers the rotational speed of the freezing chamber fan or temporarily stops the operation of the freezing chamber fan while increasing the rotational speed of the compressor in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         6 . A control method of a refrigerator in which a freezing chamber evaporator is provided at an upstream position as compared to a position of the refrigerating chamber evaporator, and having a freezing operation mode and a simultaneous freezing/refrigerating operation mode, comprising:
 determining whether or not the refrigerator operates in a simultaneous freezing/refrigerating operation mode; and   changing a rotational speed of at least one of a freezing chamber fan and a compressor so as to increase evaporation latent heat of a refrigerant introduced into the refrigerating chamber evaporator, when the refrigerator operates in the simultaneous freezing/refrigerating operation mode.   
     
     
         7 . The control method according to  claim 6 , wherein the changing of the rotational speed of at least one of the freezing chamber fan and the compressor includes lowering the rotational speed of the freezing chamber fan in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         8 . The control method according to  claim 6 , wherein the changing of the rotational speed of at least one of the freezing chamber fan and the compressor includes temporarily stopping the rotational speed of the freezing chamber fan in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         9 . The control method according to  claim 6 , wherein the changing of the rotational speed of at least one of the freezing chamber fan and the compressor includes increasing the rotational speed of the compressor in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         10 . The control method according to  claim 6 , wherein the changing of the rotational speed of at least one of the freezing chamber fan and the compressor includes lowering the rotational speed of the freezing chamber fan or temporarily stopping the operation of the freezing chamber fan while increasing the rotational speed of the compressor in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         11 . The refrigerator according to  claim 1 , wherein the refrigerant is a non-azeotropic refrigerant mixture. 
     
     
         12 . The control method according to  claim 6 , wherein the refrigerant is a non-azeotropic refrigerant mixture. 
     
     
         13 . A refrigerator comprising:
 a compressor to compress a refrigerant;   a refrigerating chamber evaporator to cool the refrigerating chamber;   a freezing chamber evaporator to cool the freezing chamber, and provided at an upstream position than a position of the refrigerating chamber evaporator; and   a controller to control an operation of the compressor,   wherein the refrigerator has a freezing operation mode and a simultaneous freezing/refrigerating operation mode, and the controller changes the rotational speed of the compressor so as to increase evaporation latent heat of the refrigerant introduced into the refrigerating chamber evaporator in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode.   
     
     
         14 . The refrigerator according to  claim 13 , wherein the controller increases the rotational speed of the compressor in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         15 . The refrigerator according to  claim 13 , wherein the refrigerant is a non-azeotropic refrigerant mixture. 
     
     
         16 . A control method of a refrigerator in which a freezing chamber evaporator is provided at an upstream position than a position of the refrigerating chamber evaporator, and having a freezing operation mode and a simultaneous freezing/refrigerating operation mode, comprising:
 determining whether the refrigerator operates in a simultaneous freezing/refrigerating operation mode; and   changing the rotational speed of a compressor as compared to the freezing operation mode so as to increase evaporation latent heat of a refrigerant introduced into the refrigerating chamber evaporator when the refrigerator operates in the simultaneous freezing/refrigerating operation mode.   
     
     
         17 . The control method according to  claim 16 , wherein the changing of the rotational speed of the compressor includes increasing the rotational speed of the compressor in the simultaneous freezing/refrigerating operation mode as compared to the freezing operation mode. 
     
     
         18 . The control method according to  claim 16 , wherein the refrigerant is a non-azeotropic refrigerant mixture.